Coming back to the TSS article, the good point to note is that author
has used OpenPortal portlet container to explore Portlet 2.0 features.
If you are associated with Portlet technology since beginning, you
might be knowing that Pluto used to be de-facto container for JSR 168
portlet development. But, after open sourcing of Sun's portlet
container implementation and hosting it as sub project of OpenPortal at
https://portlet-container.dev.java.net, it has gained lot of momentum.
Here are the things that I like about OpenPortal portlet container:

1. Fully compliant JSR 286 implementation
2. Easy installation on Glassfish and Tomcat.
3. Easy deployment/un-deployment of Portlets
4. Good tooling support for Netbeans and Eclipse.
5. Last but not least, OpenSource and FREE :)

The author at TSS has provided link for download page of App Platform
SDK, which is a GF + Portlet Container + WSRP bundle. If you already
have Glassfish install, you can download Portlet Container 2.0 binary and deploy
it on GF in secs. So, happy portlet writing.